Concrete is the most consumed man-made material in the world. A typical concrete is made by mixing cement, water and aggregates such as sand and crushed stone. Cementitious materials have been synthesized from limestone and shale, which are the calcium and silica sources, respectively. The raw materials are ground either together or separately and then fired together to form calcium rich calcium silicates. This process requires very high temperatures such as 1500° C. Portland cement, for example, is made by burning a mixture of ground limestone and clay, or materials of similar composition in a rotary kiln at a sintering temperature of 1450° C. Portland cement manufacturing is thus highly energy-intensive and releases considerable quantities of greenhouse gas.
There is an ongoing need for improved cement production methods that significantly reduce the energy requirement, are more environmentally friendly, and give rise to improved product performance. For instance, improvements that allow production at lower temperatures and/or with a broader array of source materials are desirable.